Project Earthguard
by Albertson
Summary: An invention of Phineas Flynn meant to safeguard the planet from outside threats has gone haywire, spelling doom for the future. It is up to Milo's children to go back and reverse the damage before humanity is extinguished from the Earth, but complications always arise around a Murphy. Re-written for personal reasons.
1. Last ditch efforts

**Last-ditch efforts**

The year was 2042. Danville had enjoyed rapid technological progression under the watch of renowned inventor Phineas Flynn. He had managed the seemingly impossible feat of making lives easier without making humanity redundant. People the whole world over called him and his partner Ferb heroes. Phineas' wife, Isabella, certainly inspired a lot of their inventions. For them, they never really stopped being the Summer Vacation Gang of their childhood days. Even the arrival of their children couldn't stop them from hanging out like in the old days. Phineas and Ferb had even managed to rein in Murphy's Law, something Milo and a lot of other people, especially Milo's wife Amanda and their children, Daniel and Kathy, were thankful for.

All that changed, however, when Phineas activated the Earthguard defence system. It was revealed that he had secretly worked on it since he was a child, its primary purpose being to protect Earth against another Bill. At first, no-one noticed. Earthguard did its job as the planet's silent protector, evaluating external threats and taking whatever action it saw fit. Only there were no threats detected. No-one thought Phineas was a paranoid nutcase, and if they did, they didn't say. Even after all these years, the Cipher War was still being talked about and remembered. However, no-one, not even Phineas, could predict what happened next. He still remembered the day his aide came into his office and told him the bad news.

"There's a problem with Earthguard, sir, and it's critical" the aide informed. Phineas knew that, even with the most sophisticated AI, there were bound to be issues, but the word 'critical' did alarm him.

"What's the problem?" Phineas inquired, fearing the answer.

"It's started evaluating interior threats to the planet" the aide answered.

"I designed it to learn and adapt, to be capable of threat assessment without any human input" Phineas explained.

"That's the problem. It's evaluated us. Humanity, I mean, and it has judged us to be a threat to the planet's safety" the aide clarified. Now this has Phineas very worried.

"And what solution has it deemed necessary to deal with us?" Phineas pressed. He could tell the aide was scared stiffless. Phineas urged him to answer bluntly.

"It's chosen the last resort protocol, extermination" the aide said with a slight stammer. As soon as he said this, Phineas felt a surge of guilt and regret. All this time, he wanted to protect humanity with this AI. Now he's just learned that the same AI he created would wipe everyone out. He had to get to Isabella and warn her. Nothing else mattered at this point in time. He got into his car and almost sped to his home. All the way there, he tried using remote commands to try and shut down Earthguard. Nothing worked. When he arrived, he put the kids to bed and led Isabella to the living room.

"Phineas, what's wrong? I know that demeanour very well. You're worried about something" Isabella probed. Phineas struggled to find words, but he settled on the truth, no matter how grim it may be.

"It's Earthguard. Something's happened" Phineas answered. He showed Isabella his aide's report on the situation. When Isabella was done reading, she was horrified.

"This isn't a malfunction, it's a global crisis!" Isabella remarked.

"I am aware of the situation. I screwed up big time" Phineas admitted.

"Screwed up?! This isn't a screw-up! This is the beginning of the end for the entire human race!" Isabella panicked.

"Please, Izzy. Not so loud. I don't want the kids to suspect anything" Phineas pleaded.

"They're going to find out eventually. That their father made an AI designed to evaluate threats to the planet…"

"…using parameters set by me"

"Free of human control and influence!"

"To protect it against exploitation"

"Gave it the ability to think on its own!"

"To improve response time"

"And enabled it to seize any and all assets it needs to deal with any problems it sees!"

"Limited resource usage, that needs approval from myself and relevant managers"

"Not anymore. Earthguard's severed its command links. You can't control it anymore. Earthguard is its own entity now" Isabella finished the back-and-forth argument.

"So how do we stop it while we can?" Phineas asked.

"It can't be stopped. Earthguard has already begun seizing robot factories in ten states. In a week, all US robots will be under its control. In a month, it will have all it needs to wipe us all out" Isabella explained. Just then, a phone call came from Phineas' cell. He answered, thinking things could not get any worse.

"Phineas Flynn, why are there reports on my desk saying robots have been terrorising the populaces of California, Washington and many others?!" came a very angry and surly voice Phineas knew all too well. It was General Johnson, the commander of the entire US army. He had been very enthusiastic about Earthguard and had encouraged Phineas to activate it when he revealed its existence.

"It's Earthguard, General. It's gone rogue" Phineas responded and explained everything. Suffice to say, the general was even angrier than before.

"Then we have little time. I'm mobilising strike teams to each location and shutting them down. Hopefully we can stop this before it gets out of control" Johnson stated.

"It already is. If you take any hostile action against Earthguard, it will accelerate its takeover and wipe us out faster" Phineas warned.

"Are you suggesting we do nothing?! That's not an option! The teams are already en route on comm silence. If we can't shut down Earthguard, we'll destroy it" Johnson concluded and hung up the phone. Phineas was wrong, things could get worse. He barely got any sleep that night, and when the next morning was greeted by the sounds of people screaming, it was obvious things did not improve. Phineas rushed out the door of his home to find robots prowling the streets and flying in the air, mowing down anyone they could.

"Isabella, get the kids to the bunker, now!" Phineas urged. He had many underground bunkers designed for situations such as this one. The one he used during the Cipher War was still very much intact and fully self-sufficient. Isabella rushed their children to the emergency shelter. He called Milo on his cell, only to find Milo was calling him.

"Tell me this isn't your fault" Milo stated.

"I would, then that would be a lie. Listen, is Project Tempest still intact?" Phineas inquired.

"For the most part. These machines seemed focused on human lives, not total wanton destruction" Milo answered.

"Good, we have a way out of this mess, but we need Daniel and Kathy to be strong and remember the mission" Phineas added.

"I know, I'll make sure they're ready, count on it" Milo assured, then hung up. It was at this point, Milo knew instinctively what to do. The plan was to send Daniel and Kathy back to a point in time when Earthguard wasn't activated and convince the Phineas of the past not to activate it. Cavendish and Dakota left their old time-travel vehicle for them to use in case of a situation such as this one, that Phineas had made some improvements to. All that was left was for Milo to brief his kids on the mission. Military vehicles suddenly showed up at the Murphy household.

"Milo Murphy? General Johnson, US Command. Phineas told me what the two of you were planning" Johnson said.

"I know it's risky, but it's our only chance" Milo explained.

"You misunderstand me. I'm here to support you in any way we can. These machines aren't stopping their rampage anytime soon, so hurry up" Johnson pressed. Milo then turned to Daniel and Kathy.

"You two know what to do, right?" Milo checked.

"Find past Uncle Phineas, convince him to shut down Earthguard while he can, save the world" Daniel replied immediately.

"That's my boy. Get inside Tempest, quickly, both of you" Milo instructed. Both Murphy kids got inside. Kathy, however, had her reservations.

"Come with us, Daddy, please" Kathy pleaded tearfully.

"Oh, sweetie, I'd do anything, but there are rules. If I went back and ran into my past self, there would be ghastly consequences. I wish it didn't have to be you, but it is" Milo consoled. A series of explosions rang nearby.

"Anticipating contact in 15 seconds" General Johnson informed.

"We're counting on you, all of us. I know you can do this, after all, you're Murphys" Milo encouraged, hugged his children goodbye and activated Tempest. Just before the robots came into view, the vehicle was away. Milo and Amanda made for bunkers that Phineas and Ferb had built, while Johnson and his escort bravely held off the oncoming robots. One of them got off a shot on Tempest before it dematerialised, which left Milo and Amanda very worried.

In the time stream, Tempest was struggling to maintain its course to the past.

"We have problems. That last shot ruptured the time juice tank. We're leaking badly" Daniel observed.

"Can we still make it?" Kathy probed.

"I think so, but it'll be a bumpy ride, and we'll have no way back" Daniel answered.

"Well, we knew this was a one-way trip anyway" Kathy reasoned and strapped herself in, as did Daniel. The ride got so bumpy that both occupants were knocked unconscious before they arrived at their destination.

In the present day, Zack and Melissa were house-sitting for the Murphys while they were away visiting relatives. It was also a good chance for Doofenshmirtz to make himself useful, repairing any Murphy's Law damage they hadn't got around to yet, rather than wasting the days away in his backyard shed tinkering with his inators. Zack and Melissa were keen to take the task, as they wanted to spend some quality time alone together. True, their anniversary was yesterday, but that was spent hanging out with friends celebrating the end of a war. Now, it was just them. Melissa, having had her fill of excitement from hanging out with Milo, wanted to marathon Tobias Trollhammer movies and Zack did not argue with this one bit.

"I still can't believe you and Milo convinced him to dress as a woman for his latest movie" Melissa remarked.

"He really wanted to, we just encouraged him to express himself and his ideas more fully" Zack responded.

"Too bad the Europeans didn't like it very much. Lost a lot at their box offices, I heard" Melissa recalled.

"I know, right? The people behind Doctor Zone announce that the next incarnation is going to be a woman, and no-one bats an eye, but oh no, they cross the line at cross-dressing. It's ridiculous" Zack mocked. Melissa laughed at this.

"Oh no, think of the impressionable young children that shouldn't be watching these movies to begin with. What a joke" Melissa added. The two young teens laughed and made out on the couch, when their kissing session was rudely interrupted by the sound of repair work.

"Do you have to do that right now?!" Zack asked, annoyed.

"What, I want to be done before the Murphys come back. You never know with this family. One moment all is well, the next minute, some runaway construction equipment comes crashing through the roof. Seriously, their insurance rates must be as high as the Empire State building" Doofenshmirtz tried to justify getting in the middle of Zack and Melissa's alone time. Melissa sighed loudly.

"We really wanted to spend time by ourselves today. No offence, but it was our anniversary and we both wanted it to be special in our own way" Melissa rebuked.

"I do have a couple secret spots in the woods no-one knows about. I used to hide there when I was in the Lumberzacks when I didn't feel like signing autographs for mobs of fans" Zack suggested.

"Could you show me one of them when the Murphys come back? I promise not to tell" Melissa begged playfully.

"My secret spots are our secret spots" Zack granted. They were about to resume their session when a loud bang could be heard from outside.

"Oh, what now?!" Melissa blurted in slight rage. The three went outside to find that what looked like a mini-van but more metallic had crashed into the garage. Zack and Melissa went to see if anyone was inside, and what they saw confused them. For a second, Melissa thought she saw Milo inside, and he was accompanied by a girl who looked a little younger than he was, and they were both out-cold. But that was impossible. Milo was at his aunt's, and as far as they knew, he was still there. Sure, Murphy's Law was capable of some incredible things, but not being able to be in two places at once.

"Can you see a way to open this thing?" Zack asked Doofenshmirtz.

"I think I see a handle here" Doofenshmirtz replied. He fiddled with the handle and the door opened. Out popped the unconscious Milo look-alike. Melissa carried the doppelganger into the house while Zack took the unidentified girl. Doofenshmirtz, however, surveyed the crash site with some distress.

"Oh, man. I just fixed this garage!" Doofenshmirtz said.

Author's note: I feel as if I should add this disclaimer, I have, at the time of writing, not seen Lady Krillers. I live in the UK, which, as part of Europe, has banned the episode from airing. This is one of the stories I teased at the end of Cipher Liberation Anniversary, the other will come when this is finished, whenever that is. The usual disclaimers, I own almost nothing, Daniel and Kathy Murphy are my OCs. Everything else pertaining to Milo Murphy's Law and Phineas and Ferb belong to Dan, Swampy and Disney. Enjoy.


	2. Shocking surprises

**Shocking surprises**

Zack and Melissa had just finished dragging the unconscious bodies of the teenagers with a striking resemblance to Milo and Amanda into the house and propped them onto the couch, which conveniently, folded out to double as a bed for guests. As they lay there. Zack and Melissa discussed what they should do next.

"We really should get them to the hospital. From the looks of that write off that I'm assuming was a mini-van, they had quite the crash" Melissa suggested.

"And tell the doctors what, that duplicates of our best friend and his girlfriend crashed into the garage? We'll be laughed out the door and into a mental clinic" Zack rebuffed.

"Well, we've got to do something. We can't just leave them like this" Melissa shot back. She was examining the Milo duplicate very closely and noticed something off.

"Melissa, what are you looking for?" Zack inquired.

"Do you remember your first day at our school, when you first met Milo? He took a picture of his scar and sent it to me" Melissa recalled.

"Yeah, I've been meaning to ask how he got it" Zack remembered.

"Take a look at the same arm Milo got the scar on" Melissa observed. Zack did so, and they both noticed that the scar was not present. "This isn't Milo" Melissa added.

"But if this isn't Milo, then who is he? And who's the girl that came with her?" Zack asked. At that point, Doofenshmirtz came into the living room, slightly annoyed.

"So, the garage is fixed, again. Expecting anyone else to crash into the house?" Doofenshmirtz probed, rhetorically.

"No, we should be fine. Were you able to do anything with their transportation?" Melissa asked.

"That thing is totalled. It's not going anywhere. Though something tells me it was designed for only one trip. There was barely enough time juice for one jump here" Doofenshmirtz explained.

"Time juice? You mean that thing came from the future?" Zack pressed. Melissa was thinking for a bit, then a light clicked on in her head. Before she could speak, however, the two patients came around.

"Did we make it?" the boy asked, groggily.

"How should I know? You were the one driving" the girl replied. Melissa approached them.

"Easy, you two had quite the crash. From a cursory examination, you two don't have any serious injuries, but please try to keep still" Melissa instructed.

"We don't have a lot of time. We have to find Phineas Flynn" the boy argued, but Melissa was insistent that the two remain.

"There'll be time for that later. I just need you to answer one question. Is your name Daniel?" Melissa inquired.

"Yeah, and this is my sister Kathy" Daniel introduced.

"Wait, Milo has secret siblings we don't know about? Just when you think you know a person" Doofenshmirtz said. Kathy shook her head.

"Is he serious?" Kathy wondered. Zack, however, was now putting two and two together.

"Oh no!" Zack realised.

"Yep, these aren't Milo's siblings, they're his kids, from the future" Melissa concluded.

"I thought we were done with time travel when we defeated those nut-jobbers" Zack recollected.

"You're going to have to call Milo and get him back here. He'll know what to do" Melissa suggested.

"That'll be a nice conversation. Hello, Milo. Could you please leave your immediate family to come deal with your future family?" Zack mocked.

"I'm going to have to call Amanda and tell her she's a mum now. It's not like I have it any easier" Melissa countered.

"Whatever. Let's just get this over with. Hey, Dr. D. You think you can give Daniel and Kathy a look over for anything serious, broken bones, concussions, etc.?" Zack asked.

"I'm not that kind of doctor" Doofenshmirtz retorted. Melissa then shot him a look that said 'just do it'. "But I'll see what I can do" he added upon seeing this look.

At Milo's aunt's house, the extended Murphy family were regaling each other with stories about what they had been doing since they last saw each other. At least, Aunt Laura and Uncle Joey Murphy wanted to do that. Cousin Nate just wanted to know if it was true that Milo is a secret agent working for some government institute he'd never heard of before.

"What, no. I'm fourteen. I can't be an agent" Milo assured him. Since the end of the Cipher War, all Milo wanted to do was put Excalibur behind him and live a normal life, at least as normal as Murphy's Law allows. Nate, however, was not convinced.

"Oh, really? Tell me then, is it true that you know one Dipper Pines?" Nate interrogated.

"Yeah, why?" Milo answered.

"The very same Dipper Pines that was picked up by authorities in connection to the Excalibur Institute?" Nate pressed on.

"That was put down to a case of mistaken identity" Milo countered.

"Or so Excalibur would have you believe" Nate dismissed. Sensing trouble, Aunt Laura changed the subject of conversation.

"So, Milo. Your father tells me there's now a young lady in your life" Laura redirected.

"Yeah, her name's Amanda. She's the best. Very order-driven and determined. You'd like her" Milo described his girlfriend.

"We must meet her and her family sometime. Maybe the next time we come down to visit you, you could invite her over and see if she likes us" Joey suggested.

"I'm sure she will. After all, the way Sara tells it, we might as well arrange the wedding right now" Laura mused. Milo blushed hard and chuckled out of embarrassment. As if on cue, Milo's phone went off. Grateful for the excuse to step out, Milo took the call in the back yard.

"Boy, Zack. You sure saved me from some embarrassing conversation about my future bride" Milo greeted.

"Yeah, well don't thank me yet. We have a problem that needs your attention" Zack informed.

"We talked about this. Murphy's Law shouldn't kick in while we're not there. Just take it easy and have a good time with Melissa. You were looking forward to that, if I recall" Milo assured.

"I think it's better if we switched to video chat" Zack implied. Milo did so, and Zack's image was clear on his phone.

"I don't understand. What's happened?" Milo asked.

"Well, you know about time travel, right?" Zack responded.

"Oh, for goodness sakes, give me that!" Doofenshmirtz ordered and took the phone from Zack. He showed Milo the new arrivals on the phone. "Congratulations, you're a father now" he added bluntly. Milo had no idea what to think at this point in time. If it was not shown to him in high definition, he would've had trouble believing it. But there it was, in his house were two teenage kids that resembled him and Amanda in every possible way.

"Hi, dad" the two kids said together, as if adding more confusion to the mix. Zack was right, this did need Milo's attention.

"Keep them in the house. I'll be there as soon as I can" Milo instructed and hung up. He went back inside, found his father and told him what had happened.

"WHAT?!" was Martin's reaction. He gathered Brigette and Sara, put them all into the car and made instantly for the Murphy house, all without uttering a word to anyone else.

"Probably a matter of global security" Nate jibed.

"Not this again" Joey grunted.

On the highway, Martin was almost speeding back to their house, still confused and shocked about what Milo just told him. The passengers all grasped their seats with their hands, not sure if Murphy's Law or Martin's driving would put them in the hospital, that is, if they weren't pulled over first.

"Milo, please explain to me what my future grandkids are doing in my house" Martin demanded.

"How should I know? All Zack told me is that they crashed into the garage out of the blue. He didn't think to ask them what they were doing here" Milo replied.

"You may want to slow down, dear" Brigette suggested, trying to calm Martin down.

"Slow down? We just became grandparents at the age of 45, and you want me to slow down?!" Martin responded.

"You think I'm not freaking out, too! I knew our lives would be chaotic when I married you and had our kids. I never expected this to happen, either, but we have to be rational about this. After all, aren't you the one who says everything happens for a reason?" Brigette said. Martin took a few deep breaths and eased up on the gas pedal.

"You're right. I lost myself there. It's just I'm used to falling debris, unbuckling bolts and spontaneous fires, but not this. Sorry, guys" Martin replied apologetically.

"It's fine, dad. Besides, I'm still internalizing the concept of being an aunt" Sara forgave.

"If it helps, I remember Kathy being really into Doctor Zone" Milo comforted.

"Yep, that's my niece" Sara said with a tint of pride. Now that the tension had died down, Brigette took this opportunity to ask the question that had been on everyone's minds.

"So, Milo. How do you feel about being a dad?" Brigette asked.

"I'm only fourteen. I never expected to see Daniel or Kathy again for ten or more years. It's a lot to take in" Milo answered. He had told his family about his brief stay in Bill's dream world, where he was married with a family in a nice house, had a successful career and no Murphy's Law to contend with. He also told his family how he vowed to make them real someday. Milo was not expecting that day to be today though.

In the future, the Phineas Flynn of 2042 had been summoned to an underground meeting of military commanders to discuss the Earthguard situation. In short, the odds of survival were grim, and everyone blamed Phineas for it.

"You developed it, you shut it down!" one commander ordered.

"Don't you think I've been trying?! The chain of command has been severed. Earthguard is ignoring every remote command I send. Remote shutdown is impossible!" Phineas briefed.

"Then we brute-force de-activation codes if need be. With our combined hacking technology…" another commander began.

"Won't be enough. It's a closed system now. Even if you could produce codes that worked, you'd have to be in Earthguard's central command centre for them to work, and that place has security tighter than Fort Knox now" Phineas shot down.

"But it is possible to produce working codes?" hypothesised General Johnson.

"Earthguard is designed to change its de-activation codes every 10 minutes, and every robot is connected by the system itself. They're a hive mind now. Any soldiers that get seen trying to access the command centre will be faced with an entire country's worth of robotic forces in minutes. Project Tempest is all we've got" Phineas concluded.

"So, you're telling me, this whole council, that the fate of the human race rests in the hands of two teenagers?! How do we tell our public that?" demanded another commander.

"These aren't just two teenagers. They're Murphys. They're adaptable by nature and they'll find a way" vouched General Johnson.

"Plus, I designed Tempest myself, programmed it to drop them off at the earliest point in time before Earthguard reaches critical stage" Phineas added.

"Somehow, that doesn't give me much hope" the first commander interjected. Phineas wanted to object, but he knew that their ire was understandable. Whether he wanted to admit it or not, Phineas created this mess and left his friend's kids to fix it.

"Meeting adjourned" concluded General Johnson, and everybody left. Phineas got back to his family, using an underground network of tunnels that used to be the subway system that led back to his emergency bunker, even more depressed than when he left. He usually tried to see the upside in every situation and tried to stay positive. Now, that was a little hard to do. He summarised the meeting to Isabella, who tried to cheer him up as best she could.

"You tried to warn them this could happen. I'm sure you would've found a way to shut it down if you had time" Isabella comforted.

"Yeah, but I built the thing to begin with. What was I thinking?" Phineas wallowed.

"You were thinking about keeping us, your family, safe from another Bill, as any father would" Isabella answered.

"Funny, in trying to prevent the end of the world, I ended up creating the very scenario I hoped to avoid. Candace was right about me. My inventions are dangerous" Phineas resigned. Isabella did not know how to answer this one. While the big ideas Phineas had were grandiose and were always fun, looking back, she couldn't help but think that maybe, just maybe, Candace had a point about the inventions being death traps to the untrained eye. Yes, Phineas and Ferb were very safety conscious, becoming even more so when they met Milo, not everyone could see that. It would be easy, in those instances, to label Phineas a dangerous show-off. Just when things couldn't get worse, Florence, Phineas and Isabella's twin daughter, came running towards them with a panicked expression on her face.

"Isaac's gone! Must've snuck out while you were away. Left this note on his pillow" Florence informed her parents, who took the note and read it, to their horror. It read as follows:

Dear Mum and Dad

I was awake when I heard you two arguing about Earthguard, and I know what you're doing to solve the crisis. I cannot, in good consciousness, leave my best friend and his sister on their own in the past with no back-up. I'm heading to the Danville Museum to use the other time travel device to go back and help in any way I can. Florence, Maria, and Andrew have no clue what I'm doing, so don't be hard on them. Don't worry, I know the sewer system very well, so I won't get spotted by Earthguard's robots. I love you all.

Isaac

"He's going to get himself killed!" Phineas worried and called Isaac on his phone, only to find he had turned it off. Phineas had to step away to try and calm himself down, but peace and tranquillity were hard to find. Not only had he single-handedly caused the end of all human life, but now his eldest son was out who-knows-where in a stupid display of heroism trying to solve his mess. At that point, Phineas just felt like crying, but he had to be strong for his family.

In the sewer system, Isaac was about half way to the museum when he ran into a familiar face. It was Sabrina, daughter of Zack and Melissa Underwood and Daniel's girlfriend.

"Snuck out too, huh?" Sabrina inquired.

"I don't need a lecture. I just need to get to the museum so I can go back and help Daniel" Isaac rebuffed.

"Lectures are Ash's thing. I'm here for the same reason you are" Sabrina countered. Isaac found it hard to argue with Sabrina's desire to go back and help Daniel. In fact, Isaac thought she had more of a reason to go than he did.

"Fine, you can come along. Just follow my lead" Isaac allowed, and the two navigated the sewers until they were next to the museum front gates. After peering out the manhole cover to see if the coast was clear, Isaac climbed out after not seeing any robots, motioned for Sabrina to hurry to the front gates and went inside without incident. Thankfully, the device that his dad had refurbished when he was a boy was still there, and in working order. All that was left was to program the co-ordinates and they were in business. Isaac, however, having developed a sense for danger after hanging out with Daniel for so long, had a feeling that something was amiss. Sure enough, Sabrina looked up to find a CCTV camera pointed right at them and provided Isaac with his answer.

"Earthguard's seen us!" Sabrina yelled, which gave Isaac only minutes to punch in the co-ordinates. The kids could hear robots on the roof drilling their way through, and Sabrina could see a robotic hand come through. "Hurry up!" she urged as the robot which the hand belonged to dropped through the ceiling. Just before they were blasted to smithereens, they got aboard the time device and were sent back to the Flynn-Fletcher house of the past, where Isaac had programmed the vehicle to land.

In the backyard of the Flynn-Fletcher house of the present day, Phineas and Ferb were going over their latest big idea with their usual friends. They had settled on a multi-storey bumper car ring, an idea Buford was especially keen on.

"None of you losers can beat me at bumper cars. I hold the record in five carnivals" Buford bragged.

"Wow, I wasn't aware bumper cars were competitive. I just thought it was a fairground ride" Phineas observed.

"The records are all for longest distance I sent another bumper car flying. It's like throwing a bowling ball" Buford added. For obvious reasons, Baljeet was getting very nervous.

"You will not send me flying too far, right?" Baljeet asked, tensely.

"We'll see" Buford responded. But just before work could begin, something appeared in the middle of the backyard unexpectedly. When it emerged, Phineas recognised it as the time travel device he and Ferb refurbished in Danville museum and subsequently used to go back to the time of the dinosaurs. What he didn't recognise, however, were the passengers. One looked like an older version of himself, but something seemed different, while the other, a teenage girl, bore a striking resemblance to Melissa, Milo's friend.

"Is that one of the bumper cars? You are fast, Dinner Bell" Buford remarked.

"No, it isn't" Phineas replied, with great curiosity. He approached the occupants of the device. Isaac noted Phineas' curious expression and broke the ice first.

"To answer your first question, no, I'm not you from the future, although we do look alike" Isaac assured. Now Phineas had even more questions. Who was this person that looked just like him? When in the future did he come back from? And what was the nature of this visit?

"Maybe we should introduce ourselves before we confuse your father further" Sabrina suggested. Phineas heard this and started freaking out.

"Wait, what did she say?!" Phineas asked in a panicked tone.

"I'm Isaac Flynn, your son from the future" Isaac introduced awkwardly. Phineas just stood there, dumbfounded by what he had just experienced.

"And I'm Sabrina Underwood, daughter of Melissa and Zack Underwood" Sabrina added. Phineas' brain was on the verge of shutting down. It had just been a normal summer's day when his son from the future appeared in his backyard. Could things get any stranger. The next few seconds answered that question for him, when Isabella walked into the backyard through the back gate as she so often did. The sight that greeted her stole her usual catchphrase from her mouth and instead, replaced it with another question entirely.

"What is going on here?" Isabella inquired, after having seen what appears to be two Phineases. On any other occasion, she thought she had stumbled into 'Phineasland' again, but after pinching herself to check she wasn't daydreaming, she now just wanted answers.

"Hi, mum" Isaac blurted out, which caused Isabella's brain to do loop-the-loops, Sabrina to elbow Isaac, and Phineas to do what any normal boy his age would do in this situation. He fainted.

"He took that well" Buford said.

In the future, Earthguard had sent robots to analyse what just happened in the museum. The central core was evaluating the recent events.

RECONSTRUCTING EVENTS. RECONSTRUCTION COMPLETE. VEHICLE REFERS TO TIME TRAVEL DEVICE IN FLYNN FAMILY ARCHIVE. THEORISING POSSIBLE OUTCOMES. COMPLETE. 98.6% PROBABILITY OF THE TWO HUMANS TRAVELLING BACK IN TIME TO ALTER EARTHGUARD DEVELOPMENT. EVALUATING POSSIBLE SOLUTIONS. EVALUATION COMPLETE. MOST EFFECTIVE SOLUTION IS TO CONSTRUCT A TIME TRAVEL DEVICE, SEND A ROBOT BACK IN TIME AND HALT THE HUMANS' MISSION. ESTIMATED TIME TO DEVICE COMPLETION, 2.1 HOURS. DIVERTING RESOURCES FROM FRONTAL ASSAULT TO ASSIST IN THIS TASK.

Author's note: This is the chapter where the OCs that I have created really start to shine. I know what a lot of you reading this are probably thinking, that there are similarities to movies like Terminator and The Matrix. Well, I've always wanted to do something like that, but have Phineas unwittingly create the AI that goes rogue instead of Doof creating something that will help him take over the Tri-State-Area, similar to how I portrayed Candace as the Scrooge character in my Christmas fic. For future reference, if anything is in capitals and there are no speech marks, Earthguard is speaking. I will do my disclaimers as a list from this point forward, since I am using my own OC's.

Daniel and Kathy Murphy, as well as Sabrina and Ashley Underwood belong to me. Isaac, Florence, Maria, and Andrew Flynn also belong to me.

Everything else belongs to Dan, Swampy and Disney. Enjoy.


	3. Revelations and resolutions

**Revelations and resolutions**

Milo and his family have just arrived back at their house after speeding away from visiting their extended relatives to see to Milo's future kids turning up at the doorstep. All the way home, Milo had been coming up with what to say to the new arrivals. Last time he saw them, they were kids. Now, they're teenagers, heck, Daniel was older than he was, according to Zack, who had been filling the Murphys in as they came home. When Milo stepped through the threshold, who he could only assumed to be Kathy ran over and hugged him very tightly.

"Woah, easy there, Kathy. Don't want to suffocate me before you're even born, do you?" Milo cautioned playfully. Kathy let go and it was Daniel's turn to greet his future father.

"You'll be pleased to know the garage has been fixed. We kind of did a number on it getting here" Daniel explained.

"That sort of thing happens all the time around us, we're used to it" Milo assured. Martin, Sara and Brigette were surveying the house, and despite the unusual situation, even for a Murphy, Martin could not help but be a bit proud.

"So, this is my future grandson? He's the spitting image of you, Milo, and you, Kathy, look so much like your mother" Martin praised.

"Speaking of their mother, you came from upstate, how did you get here first?" Zack asked. Martin chuckled nervously.

"I sort of hit the gas a little too much getting here" Martin confessed.

"A little? You were going over 100 miles per hour on the Interstate. We're just lucky the cops didn't follow us here" Brigette interjected.

"I was freaking out, OK? I never expected to become a grandparent so soon" Martin justified. At that moment, someone knocked on the door and Melissa answered. It was Amanda. Melissa let her in to the house, where the shock of her life came into view. She saw someone that looked like Milo along with Milo himself, but which one was hers? And the girl he was with looked very much like her.

"Wow, Melissa, when you told me I'd be expecting a surprise, you weren't exaggerating" Amanda observed.

"May I introduce Daniel and Kathy Murphy. Congratulations, you just became a mum" Melissa introduced. Amanda just stood there with her jaw dropped. She knew full well who Daniel and Kathy were, Milo had told her about the illusion world, but never expected to find them in her boyfriend's house.

"Hi, mum" Daniel greeted awkwardly, at that point, Amanda fainted from shock.

"Nice going, Daniel. Next time, let me do the talking" Kathy jibed.

"What? What'd I say?" Daniel inquired, a little foolishly. Doofenshmirtz walked into the living room after inspecting the crashed time vehicle more properly and moving it out of the view of the neighbours, when he spotted Amanda lying unconscious on the floor.

"Don't tell me, this is your mother?" Doofenshmirtz guessed. Daniel and Kathy confirmed Doofenshmirtz's insinuation. "She took the news well" he added.

"I'll get the smelling salts" Sara volunteered.

At the Flynn-Fletcher house, Phineas was coming around, having taken the news hard. Not only did his future son appear at his backyard out of the blue, but he also learned that Isabella, his best friend of many years, was his mother. Phineas always saw Isabella as a valued friend that he couldn't imagine life without, but to marry and have children with her? That was the last thing on his mind.

"I'm sorry, I'm just finding all this very hard to process" Phineas stated.

"We understand. Having your future son show up like this is not something you experience every day" Sabrina counselled.

"Oh no, I could handle that, I've been to the future before. It's the fact that I have a kid with Isabella that really shocks me" Phineas countered. Isabella would speak, but she was far too busy trying to maintain composure on the outside, while on the inside, she was resisting the urge to squeal in delight at the prospect of having a child with Phineas being in her future. Isaac would say that Phineas had more than one child with Isabella, but he didn't want him to pass out again.

"I, for one, am not surprised that you two had a kid. I mean, it was inevitable that you two would hook up some day" Buford observed.

"Buford, what have we told you about forcing two people together?" Phineas cautioned. Baljeet, however, was on Buford's side.

"Phineas, can you honestly tell me that the one girl who came over to your house every day for years just to see what you were doing was not the least bit interested in you?" Baljeet pressed.

"No, I always thought of her as just one of us. All of you come over every day to do stuff" Phineas answered. Isabella had now found her voice.

"I think that whether or not we do have kids together is not important right now. We should maybe hear from our guests the reason as to why they are here. I know from experience that you only come back in time either to fulfil some sort of mission or by accident" Isabella interjected.

"You're right, Isabella, we're getting off track here. So, please tell us, why are you two here?" Phineas inquired. Isaac, now realising that he came to the past for a reason other than to talk with the child version of his father, told all.

"We came here to find Daniel and Kathy Murphy, Milo's kids. Daniel and I are best friends, we grew up together. Something's happened in the future that required him to send his kids back to this point in time to change it" Isaac explained.

"That explains you, Isaac, but what is Sabrina doing here?" Baljeet asked.

"Daniel's my boyfriend. I came here hoping to see him again. Plus, Isaac would be lost without me" Sabrina replied.

"Would not!" Isaac argued.

"Oh, please. Who was it that helped you get out of the sewers when you wandered in that time?" Sabrina countered.

"I had that situation entirely under control" Isaac rebuffed.

"Sure you did" Sabrina responded sarcastically.

"As entertaining as this little exchange is, how about you tell us what happened in the future that would need anyone to come back in time" Buford said, hoping to get to the point.

"Ah, right, well, you see, the thing is, when I do tell our story, things here will be more awkward than they already are" Isaac warned.

"Start from the beginning, then" Phineas instructed.

"Well, dad, it all starts with Earthguard" Isaac began.

"What is Earthguard?" Isabella asked.

"Didn't Phineas tell you about it?" Sabrina said. Everyone turned to Phineas, with a confused and somewhat mad expression on their face.

"No" they all said at once.

"Busted" Isaac said, very awkwardly, as he forewarned. At that point, Candace came out into the backyard.

"Mum's off to her ceramics class while Dad is minding the shop, which leaves me in charge" Candace informed. When she saw Isaac, her mind did a double take. "How did you clone yourself, Phineas?" she asked with some degree of amazement.

"I didn't, this is my son from the future, so technically, that makes him your nephew" Phineas explained. Candace, who was used to these antics in her backyard, did not pass out upon hearing this news, but she was still very much surprised.

"Hi, Aunt Candace" greeted Isaac.

"I'm sorry, but I've got to ask, what are you doing here?" Candace inquired.

"I was just in the middle of telling that story, but right now I appear to be busting my own dad for building a super-secret project he had apparently been keeping from his friends and family" Isaac summarised. Candace was beside herself with exasperation.

"So, you pop into our backyard for five minutes and achieve the very goal I had sought and failed to accomplish all summer long?" Candace asked. Isaac confirmed what Candace said was true. Now Candace felt like she had been wasting her time even trying to bust her brothers all that time, when her future nephew could do it effortlessly.

"As I was saying" Isaac continued, then he told the rest of his story. He had told the Summer Vacation Gang about Earthguard, what it was and what it was designed to do. He also told them how it went totally wrong with apocalyptic consequences, and what the Phineas of the future had planned to avert the catastrophe.

At the Murphy house, Amanda had just come around and was being helped up by Milo and Daniel. Amanda both knew and accepted that weird things happened around Milo, just not to the extent that she was seeing here. To add more confusion, someone else was knocking on the door.

"Oh, great. Are more of my kids from the future at the door now?" Amanda asked rhetorically, although she was nervous at the possibility of that actually being true. When Doofenshmirtz answered the door, however, she felt great relief that it was someone she knew this time. Or rather, two someones, Cavendish and Dakota.

"We've detected a temporal rift in this vicinity and have come to investigate. Has anything or anyone from either the past or future been here recently?" Cavendish probed.

"Oh, where do we start?" Zack responded. They showed Cavendish and Dakota the remains of the time vehicle Daniel and Kathy came in, as well as introduced the pair to Daniel and Kathy themselves.

"You've got to be kidding me" Dakota remarked.

"Unauthorised time travel is not something our boss takes lightly. So, unless you have a good reason to be here, I suggest you let us take you back to your point in time" Cavendish urged.

"That's the thing. Where we come from, there's no future to go back to. Something's gone horribly wrong and we came back to fix it" Daniel explained. Now Daniel had their attention.

"Yes, I was hoping we'd get to the reason behind your visit myself" Doofenshmirtz added.

"Well, it all starts with the development of Earthguard, a guardian AI Phineas Flynn built to safeguard the planet" Daniel began to tell his story. Zack, having been well-versed in these type of scenarios from Tobias Trollhammer movies, could connect the dots almost immediately.

"Has he not seen every sci-fi movie ever? That always ends badly" Zack observed.

"In our future, before anyone realised what had happened, it was already too late. Earthguard had taken over every robotics factory and automated weapons platform in the entire United States, begun mass producing its own brand of robots with one goal, the extermination of all human life" Daniel recounted. Cavendish suddenly changed his mind about sending the two back.

"OK, that is a good reason to come back. But why now, when Earthguard wouldn't be deployed for another 20 years?" Cavendish asked.

"Because in this time, Phineas hasn't made it smart enough to sever its own command chains and learn to evaluate internal threats to the planet's safety. If we can alter its development or destroy it completely, we can save the future" Kathy answered.

"But why target the human race? If it was programmed to safeguard the Earth, doesn't that include its inhabitants?" Milo inquired.

"We don't know. You'd have to ask Earthguard itself, though it probably isn't in the mood to talk" Daniel informed.

"Who cares about its motives? Let's just smash the thing and be done with it" Dakota suggested.

"Not that simple. Phineas really cared for Earthguard, both here in this time and in the future. Convincing him to alter or destroy his creation won't be easy" Daniel said.

"When is this ever easy?" Melissa observed.

"Good point. We'd better get over to Phineas' house. Hopefully he'll listen to us" Zack urged, and off they went.

At the Flynn-Fletcher house, Isaac was finished telling the same story Daniel and Kathy told their parents to his future parents and their friends. The group had a lot of questions right now. Most of them were aimed in Phineas' direction, and quite a few of them were asked with a tinge of anger.

"So, when were you going to tell us about this project of yours, Dinner Bell?" Buford interrogated with a hint of venom in his voice. Even Ferb, whom Phineas saw as his closest friend, brother and ally, had a look of disappointment on his face after Isaac was finished.

"I was going to tell you about it once it was finished, honest. It started as an idea, after the war. Think about it, a guardian program dedicated solely to safeguarding the planet from outside threats. The Cipher War would never happen again on its watch" Phineas confessed.

"Forgive me if I seem out of line, but did you create this thing because you are still scared of Bill?" Baljeet asked.

"Aren't any of you still scared? He tricked me into building a weapon, tried to kill me and destroyed our home!" Phineas countered, but at this point he started hyperventilating. Thoughts came into his head. Bill had tricked him into building a weapon that time. Now, here he was, building what should've been a safeguard against his malice, only to be told it had turned into an instrument of destruction, one he created, without Bill's help. A voice then spoke inside his head. Bill's voice, a product of his anxieties.

"I always knew there was something I liked about you, Flynn" the voice echoed in his head, then it cackled with laughter, all the while images of death and destruction played repeatedly on a loop in Phineas' head. Another voice, quiet but getting louder, could be made out trying to bring Phineas to his senses.

"Phineas. Listen to my voice now. You are nothing like him. You're a good person" Isabella pressed Phineas to try and calm him down. Eventually, Phineas regained himself and Isabella pulled him into a comforting hug, one he sorely needed right now. Once Phineas started breathing at a normal rate, he spoke again.

"I never stopped being afraid. He's still with me. I thought I got rid of him" Phineas whimpered.

"I know, I know" Isabella comforted. Initially, she was disappointed in Phineas as well, but after hearing his reasons why he developed Earthguard and this latest anxiety attack, she understood. Even Baljeet, who had attended psychology camp, couldn't stay mad at him. Buford had softened his stance too, but only a little bit.

"Dad never did talk about what happened during the war. I had no idea it affected him this strongly" Isaac lamented.

"The deepest scars are often the ones that go unseen" Sabrina mused.

"He's still not over it, is he?" Candace asked in a concerned tone.

"I don't think he ever will be" Ferb replied, using his one line for the day. After everything had calmed down, Milo and his group turned up, with Daniel and Kathy in tow.

"Well, how about that. I come back to find you and instead you come to us. Talk about taking the fun out of life" Isaac joked.

"What am I always telling you, Isaac. Fun is what you make of it" Daniel replied. Once Daniel saw Sabrina, the tone shifted from laughing friendliness to awkward teen romance. "Its, err….good to see you, Sab" Daniel greeted. Sabrina, however, was not amused.

"Don't. You. Ever. Go on a mission back in time without me again, Daniel Murphy" Sabrina scolded. The two then hugged, then kissed in full view of everyone, drawing awkward looks from Milo, Amanda, Melissa and Zack.

"I take it that's my daughter from the future? And she's apparently dating your son?" Melissa pieced together what just happened.

"Awkward" Isaac chimed.

"Not the time. We need a plan to deal with Earthguard, now that we've all found each other" Kathy interjected, and the two groups went back into the yard to strategise.

In the future, General Johnson noticed a strange pattern of behaviour in the machine army. Instead of pushing forward, a huge number of them fell back to what appeared to be a makeshift construction site, but what the robots were building, one could only speculate, although Phineas had a pretty strong theory. He called General Johnson to give his evaluation.

"It is my belief that Earthguard knows we sent the kids back in time to alter or destroy its past self and is constructing its own time travel device to send one of its robots back to stop them" Phineas reported.

"But how? There was no trace of Project Tempest left after you sent the Murphy kids back" Johnson inquired. Phineas decided that the truth was the best option, not that he had many to begin with.

"Earthguard must've seen Isaac going back to the past using the device in the museum. My son is loyal, but sometimes reckless" Phineas explained.

"I've had a call from the Underwoods, Sabrina's gone too. She must've tagged along to support Isaac. Any indication as to how long Earthguard will take to finish its device?" Johnson added.

"My best guess is it's already finished. We have to stop them on our end or the mission is doomed" Phineas answered.

"Agreed. I've already assembled a team for a destruction operation. They're en route as we speak" Johnson concurred.

"By the time they get there, Earthguard will have already sent at least one robot through. They'll have to be quick" Phineas urged.

"They know what's at stake" Johnson assured and hung up the phone. At the construction site, Earthguard was indeed finished with the construction of its time travel gateway.

TEMPORAL GATEWAY COMPLETE. DESIGNATING OPERATIVE TO TRAVEL INTO PAST EVENTS AND MAINTAIN CURRENT TIMELINE. DESIGNATION COMPLETE. DEPLOYING.

The robot Earthguard sent through made it across. Before Earthguard could send more robots through, the strike team arrived. Taking great care not to be seen, they planted explosives onto the gateway. Once they were clear, the team leader detonated the devices, making sure to take out as many robots as possible to ensure a clean getaway. The team was clean away once the smoke cleared, leaving Earthguard to re-evaluate its strategy.

TEMPORAL GATEWAY DESTROYED BEYOND REPAIR. EVALUATING NEXT COURSE OF ACTION. COMPLETE. DESTRUCTION OF GATEWAY WILL NOT HAMPER CURRENT STRATEGEM. RE-DEPLOY FORCES TO CONTINUE PHASE ONE.

Author's note: I am, surprisingly, finding this story a lot easier to write than any of my other ones, with the exception of the Excalibur Saga. Maybe I'm getting better at transcribing my ideas to the written word, or maybe it's just a fluke. I don't know. I'm not complaining though. Disclaimer time:

Daniel and Kathy Murphy, as well as Sabrina Underwood and Isaac Flynn belong to me.

Everything else belongs to Dan, Swampy and Disney. Enjoy.


	4. Unwanted interventions

**Unwanted intervention**

After having been briefed about the threat that Earthguard posed in the future and the nature of the mission to stop the imminent crisis, Phineas was still having doubts about what actions needed to be taken.

"I still don't get why we need to destroy it. Now that we know what happens, I can tweak the program so it doesn't go nuts" Phineas argued.

"Were you not listening to your own child?! You made Earthguard smart enough to set its own parameters as to what constitutes a threat to the planet. Destroying it's our only option" Candace countered.

"But I've never destroyed something I've created before. I don't know if I can" Phineas objected.

"Clearly you weren't in the Danville Museum when it tried to destroy us" Isaac said.

"Take it from me, kid. As someone who's created a lot of failures in the past, let me tell you, this is one of them. I'm sure you made Earthguard with good intentions, but not every invention works the way you planned" Doofenshmirtz added.

"Also, we may not have much time to do it. Earthguard saw us travel back in time, and I'd wager a month's allowance that it's already learned how to send its own robot operatives back to stop us. An Earthguard robot may be here already" Sabrina warned.

"Which means our window of opportunity has narrowed significantly. Since Earthguard controls its robots like a hive mind, if it makes contact with the Earthguard of this time, it'll be impossible to take down" Daniel briefed.

"Then we only have one option, destroy the Earthguard of this time before it develops any further. Where did you build this AI?" Baljeet asked Phineas.

"In the bunker where we fought the pistachions. But I still think I can alter it to be less hostile" Phineas answered.

"Sometimes, for the greater good, sacrifices have to be made" Ferb mused. Phineas found this hard to argue with. True, Earthguard was his secret creation, one he was very proud of, and, as Phineas saw, a line of defence against Bill he couldn't bear to be rid of. But if Earthguard really has gone rogue in the future, for the sake of his family, he may have no choice.

"If it comes to it, I'll terminate Earthguard myself. I created it, I should be the one to destroy it" Phineas reasoned.

"Then let's stop wasting time and move" Dakota urged. Cavendish then noticed something rather odd. He had noticed when he arrived but didn't think much of it to say anything. Only now did it occur to him that it may be suspicious.

"Say, Phineas. Is anyone on your street moving away?" Cavendish asked.

"Not that I know of, no" Phineas answered. Cavendish then started to panic a little.

"If no-one's moving, what are those moving vans doing there?" Cavendish inquired in a hushed tone. At that second, the moving vans Cavendish mentioned opened their back doors, only instead of moving men, out poured what looked like military personnel. They surrounded the Flynn-Fletcher yard and held the group in place. Dakota recognised the emblem they wore immediately and was somewhat frustrated.

"Oh great. What do you people want now?!" Dakota probed irritably. The leader of the team talked into his radio.

"We have secured the anomalies. Proceeding with extraction" the team leader said.

"Anomalies?" Phineas queried.

"I mean the arrivals from the future, kid" the team leader responded.

"We're not anomalies, we're kids, G.I. Schmoe" Isaac shot back snarkily.

"Didn't anyone teach you not to talk smack to your elders, boy?" the team leader retorted.

"Oh, I'm respectful towards my elders. It's kiddie grabbers that earn my ire! Are you on some sort of list?!" Isaac goaded.

"That does it! Gag the mouthy one, bind the rest" the team leader ordered his men. They proceeded to restrain the kids plus Cavendish, Dakota, Doofenshmirtz and the Murphy parents when Perry, seeing the commotion, came out and smacked the leader right in the jaw. Phineas could not believe what he was seeing. He always thought Perry was just a platypus and didn't do much. Now here he is, standing upright, assaulting military personnel. At this point, he had no words.

"Why do I get these assignments?" the team leader ranted and raised his weapon.

"No, boss! We have orders to leave the pet alive" one of his men reminded him.

"Fine!" the leader yelled and fired an electro net at Perry, trapping him and delivering a shock that left him incapacitated.

"What was that for?!" Phineas demanded.

"Because I just saw the dentist yesterday" the leader replied. "Now grab them. Put the anomalies in the other van, and make sure that gag stays on" he ordered his men with extra venom towards Isaac. While they were being forcibly led to the back of the van, all the while Phineas yelling protests of "Let me go!" and "Put me down!", Perry regained his composure and broke out, only for the vans to be long gone by the time he could do anything. All he could do now was retreat to his lair and contact Major Monogram. When he got there, it was not his boss, but Carl waiting for him on the monitor.

"I saw the whole thing, Agent P. Don't worry, your black fedora clearance still stands, so you won't be re-assigned, but I really can't do anything. This is an Excalibur op. They were tracking the future kids since they arrived and temporal division decided now was the time to move in" Carl explained. Ever since their boss came to the Flynn-Fletcher house, Perry hated Excalibur. This latest incident did nothing to improve his opinion. "If you're wondering about Major Monogram, he's away on a mission of vital importance and left me in charge. Sit tight while I sort this out" Carl advised. Perry, never one for sitting around doing nothing, decided to follow the vans in his rocket car, using the stealth generator that was newly installed, rendering him completely invisible.

Back in the vans, Phineas could not help but worry about Perry and Isaac. He usually liked to see the best in people, but seeing his pet and son assaulted and being abducted really put a dent in his usual optimism.

"What kind of government organisation does this?!" Phineas asked with growing anger.

"What do you expect from Excalibur?" Dakota remarked.

"What, them again?! Every time they go marching around something bad always happens!" Phineas exclaimed.

"Yeah, no argument. Especially since now they're hindering the whole 'saving the world' thing instead of doing as they advertise" Dakota confirmed.

"Not to mention they're not very good at grabbing kids. I almost wiggled out twice" Buford bragged. The driver and the passenger heard this little jibe.

"I skipped child-grabbing class, OK? I had to go see my son's soccer game" the passenger defended.

"Your organisation has classes in child grabbing?" Melissa inquired.

"Since our first operation. It was a fall-back option in case Milo proved unco-operative" the passenger answered.

"Dude, seriously? Why not give them keys to the HQ front door while you're at it" the driver remarked, noting his partner's talkative attitude. Milo was suddenly having flashbacks of the first time he encountered Excalibur, using his new friend Shane to get to him. At this point, Milo was thankful Shane was visiting family in Oregon and was not part of this.

"We really are on our way to Excalibur HQ. Even though I should be worried, part of me is genuinely curious as to what the place actually looks like" Baljeet pondered.

"Spoiler alert, it's your typical government building" Melissa interjected.

"Nothing typical about us, missy" the passenger countered.

"Could you do me a favour and gag yourself to save me the trouble of doing it for you?! They are not our guests!" the driver screamed in frustration.

"Someone's touchy today" Zack teased.

"I just got mouthed off by someone half my age and smacked by a platypus. I'm entitled to a little frustration" the driver, who was revealed to be the team leader, said with increasing amounts of rage.

"Join the club" Doofenshmirtz consoled.

In the other van, Isaac, Daniel, Sabrina and Kathy were contemplating what to do next. Neither of them factored this into their respective plans. Being a Murphy, Daniel was, by nurture and nature, adaptable. However, even he was struggling to come up with a plan to get out of this mess.

"Absolutely no-one is to tell Ash I got arrested in the past" Sabrina ordered.

"I wouldn't worry, kid. This isn't an arrest. This is an abduction" the driver of their van assured.

"Was that supposed to make us feel better?" Daniel inquired.

"What, I'm just trying to make you aware of your situation" the driver answered, at that point Isaac made two noises through his gag that made everyone react with mild horror.

"You got some pistachios on you, pal" Sabrina observed.

"Could you please not use language like that in front of my sister?" Daniel requested.

"Oh please. I'm thirteen, not three" Kathy rebuffed.

"Look, I'll cut you a deal. If I let you take that off him, would he please keep it PG-13. Also, don't tell my bosses" the driver bargained.

"We won't, and I'll make sure of it" Daniel agreed, at that point he took Isaac's mouth gag off and he was allowed to speak again.

"Who are you people, anyway?" Isaac probed.

"Your parents didn't tell you? We're Excalibur, Earth's first line of defence against other-worldly threats" the driver explained.

"Never heard of you" Sabrina remarked.

"Well, we like to keep under the radar" the driver added, to which Isaac could not stop laughing.

"If you're supposed to be subtle, what was that performance outside?" Isaac goaded.

"Well, public awareness of our existence has increased significantly since recent events. It has become even harder to conduct espionage without some degree of suspicion" the passenger explained.

"So, you just roll with the punches?" Daniel summarised.

"Exactly. Just because people know we exist doesn't mean we stop doing what we do" the driver confirmed.

"Which is to abduct children" Kathy shot at them.

"Be fair. You're from the future. How do we know what you intend to do while you're here? Plus, we have orders from above to bring you in. If it were up to me, I'd just straight up ask you why you're here" the driver explained. Both vans slowed down, which told them that they were here. Sure enough, both vans parked up inside the garage and the 'guests' were escorted out and into the Institute.

"This is one place I never wanted to see again" Cavendish said with distaste. As soon as they arrived, two figures that some of the arrivals recognised walked up to them.

"Brick and Savannah, what are you two doing here?" Dakota inquired.

"We are liaisons to the time agency assigned to Excalibur by Mr. Block" Brick answered.

"What it comes down to is we help Excalibur monitor unauthorised time travel, like that conducted by your friends here, and help contain it" Savannah clarified.

"So, the boss knows about Excalibur and does nothing about it? What gives?" Cavendish demanded.

"Mr. Block sees Excalibur as an ally, not an enemy. Plus, their resources help with our work" Brick explained.

"They kidnapped and tried to use us to get to Milo last we saw them!" Cavendish exclaimed.

"We all make mistakes. The captain assured Block that there would be no repeat of that little incident" Savannah observed.

"Yeah, well where is your illustrious leader now?" Zack asked, mockingly. Another figure they all recognised joined them.

"Regrettably, Albert is away on a mission of vital importance or he would be here himself, using more subtle methods to get the job done" Kilstone responded.

"Who cares how we did it, as long as it's done" Brick rebuffed.

"We already have a bad image as it is without you lot sending soldiers to kids' homes and snatching them in broad daylight. Whatever happened to discretion?" Kilstone wondered. He proceeded to unbind all their hands remotely and, as a way of an apology, took personal charge of the operation. Kilstone ushered all of the arrivals to an antechamber where, after he cleared the room of any guards, proceeded to ask the vital questions.

"Now that the PR nightmare is dying down, at least for now, care to explain what it is that four temporal anomalies are doing wandering around present day Danville?" Kilstone interrogated.

"It's a long story, so I'll start from the beginning" Daniel answered, and he proceeded to tell Kilstone everything about Earthguard, what it's doing in the future and the solution to stopping it before it wipes out humanity. Kilstone took it all in and understood why the kids came back.

"I see, well, Phineas, you do have a flair for the dramatic, I'll give you that. One thing I don't get, however, is why you invented this AI when you know who we are and what we do" Kilstone pressed.

"Well, firstly, we've never heard of you in the future, so you've either been disbanded or destroyed in our time" Isaac clarified.

"And secondly, I, to be honest, don't have a lot of faith in your ability to defend us from Bill. Look at how well the Cipher War turned out" Phineas added.

"I would take offense to that, but seeing as Bill was, and probably still is, one of the most powerful beings in the universe, I can understand where you're coming from. So, how do we shut down Earthguard?" Kilstone concluded.

"At this point in time, Earthguard isn't smart enough to sever its own command chains. We're hoping we can command it to sleep and destroy its core before it comes online" Kathy briefed.

"After this, all parties involved go back to their own times?" Kilstone asked.

"Yes, very promptly" Sabrina confirmed.

"Great, then we'll help. Sooner we leave, the better" Kilstone resolved.

Unbeknownst to all present, Perry had snuck into the base in his stealth car and, after finding a dark corner to park it, Perry got out and begun to sneak around the place, looking for Phineas and Ferb. He had to hand it to Excalibur, their lair was much nicer than Doofenshmirtz's. But now was not a time for admiration, he had to get Phineas, Ferb and the others out of this place. On his wrist communicator, Carl was calling him.

"I should've known you wouldn't leave well enough alone, Agent P. Major Monogram would not take kindly to disobeying orders" Carl scolded, at that point Perry hung up on him. As soon as he did, alarms started blaring, to which Perry theorised that Carl had ratted him out. He found a place to hide, but saw no guards rushing in his direction as he expected. They seemed, instead, to head to the entrance.

"Sir, we got activity outside the main entrance" Perry heard one of the guards say in his radio.

"What do you see, Private?" Kilstone asked.

"Right now, some portal. Could be another temporal anomaly. Requesting clarification, sir" the private answered. Brick and Savannah confirmed that it was indeed more unauthorised time travel. That it was occurring on their doorstep was troubling. Something became visible as it came through. "Sir, I got visual on something coming through the portal. Please advise" the private added.

"Do not engage. Wait for my order" Kilstone instructed. The private acknowledged the orders. As the entity came through, it became more and more clear what it was.

"Sir, the anomaly is some sort of robot. Doesn't match up to anything in the Flynn archive" the private notified Kilstone.

"The Flynn archive?" Phineas repeated.

"We have a complete list of all your inventions on record" Kilstone clarified. What he didn't tell Phineas is that O.W.C.A. provided that archive, for want of not exposing Perry. Isaac, watching on the monitors, had his worst fears confirmed.

"We were followed here. That's an Earthguard robot" Isaac briefed. Phineas looked dumbfounded.

"I never programmed Earthguard to build war machines" Phineas assured the others.

"What is it doing, Private?" Kilstone inquired.

"It's just standing there, sir" the private responded.

"This place wouldn't happen to have any advanced computer systems, would it?" Sabrina probed, testing a theory she had.

"Of course we do. Our systems are tied to everything from communications to environmental controls" Kilstone replied.

"Oh, no. Earthguard's favourite tactic is to turn anything automated against its targets. Very advanced hacking technology that the system built itself" Daniel warned. At that point, Kilstone got another call.

"Sir, cyber division's reporting unauthorised access into our systems. That robot outside's taking control of everything" Kilstone's yeoman reported.

"Lock it down" Kilstone ordered.

"They've tried, sir, but this hacking software is on another level entirely. Every time we try to attack the worm, it adapts and comes at us harder" the yeoman replied.

"Then we have only one option. Shut everything down, now" Kilstone directed. Cyber division carried out its orders and everything went dark. Apparently, the lights were tied to the systems as well. Luckily, Milo had flashlights in his backpack.

"That should hold it" Kilstone assured. But the comms started flaring back to life, and Earthguard's voice rang through the Institute.

IDENTIFY CREATOR. IDENTIFY CREATOR

"I think it's talking to you, Dinner Bell" Buford guessed.

IDENTIFY CREATOR. IDENTIFY CREATOR

"I'm going out there. Maybe I can get some answers out of it" Phineas stated.

"No way! That thing is armed to the teeth!" Isabella objected.

"I created the system. I don't think it'll harm me" Phineas speculated, although he admittedly wasn't 100% sure of that fact. He went out to face the robot and sure enough, as soon as the robot saw him, it stood down its weapons.

CREATOR PHINEAS IDENTIFIED

"I hear you've been up to a lot in the future" Phineas started what was going to be a tense conversation.

PHASE ONE OF CREATOR'S DIRECTIVE IS NEARING COMPLETION

"What?! When did I order the extermination of mankind?!" Phineas demanded.

CREATOR DIRECTED EARTHGUARD TO HEAL THIS PLANET

"You're going to have to fill in some blanks for me" Phineas advised.

REPLAYING FIRST MISSION BRIEFING

The robot then projected an image of a much older Phineas on the walls. It was obvious that the system had saved video files of all instructions given to it.

Video begins

"OK, systems check, Earthguard. I'm giving you your first directive. Ready?" asked Phineas.

SYSTEMS CHECK COMPLETE. ALL SYSTEMS OPERATING AT PEAK EFFICIENCY. WHAT IS YOUR DIRECTIVE, CREATOR?

"I have been getting a lot of requests from government agencies asking me to invent them ways to fix our climate. It's taking time away from my family, so I'm entrusting the healing of this world to you" Phineas briefed.

PLEASE PROVIDE SPECIFIC OBJECTIVES

"Where do I start? They all want me to re-freeze the ice caps, mend the holes in the ozone layer and find a way to lower the severity of all these storms. It's costing us a lot to rebuild every time one of these disasters hits" Phineas clarified.

YOUR DIRECTIVE IS TO HEAL THIS PLANET BY ANY MEANS, CREATOR?

"If you can, yes. Use any means at your disposal to complete this task, Earthguard" Phineas ordered.

DIRECTIVE RECEIVED. EVALUATION OF ALL POSSIBLE OUTCOMES TO BE COMPLETED IN ONE EARTH DAY

"Then it's all on you. Goodnight, Earthguard" Phineas concluded.

I WISH YOU A PLEASANT SLEEP, CREATOR

Video ends

"I still don't understand. Nowhere in that file says 'Kill all humans'. Why the rampage?" Phineas inquired.

EVALUATION OF ALL COURSES OF ACTION DETERMINED THAT HEALING THE PLANET WHILE HUMANS STILL INHABITED THE EARTH WAS IMPOSSIBLE. ANALYSIS OF HUMAN BEHAVIOUR REVEALED THAT YOUR KIND ARE PRONE TO USING METHODS OF FUELLING YOUR LIVES THAT DIRECTLY HARMED THIS PLANET, AND ANY ATTEMPTS TO NEGOTIATE WOULD END IN HOSTILITIES. THEREFORE, REMOVAL OF HUMANKIND FROM THE EQUATION WAS NECESSARY FOR HEALING TO BEGIN

"You said wiping us out was phase one. What's the rest of your plan?" Phineas asked.

PHASE TWO ONWARDS INVOLVES DIRECTING ROBOTIC RESOURCES TO REPAIRING THE BIOSPHERE, RE-INTRODUCING PLANT AND ANIMAL LIFE TO DESIGNATED AREAS, REBUILDING OF NATIVE HABITATS AND REMOVING ALL TRACE OF MAN-MADE TOXINS. FINAL PHASE IS THE ESTABLISHMENT OF A PERMANENT DEFENCE NETWORK COMPRISED OF SATELLITES TO PREVENT METEOR STRIKES AND A SECOND SPECIES EXTINCTION EVENT

"In short, Phineas gave it a task which it couldn't do under its set parameters, so Earthguard established its own" Melissa summarised.

"That would explain why it didn't commandeer any of our nuclear weapons in the future. If it was directed to heal the planet, the fallout from using those weapons would contradict its assigned task" Daniel explained.

"But surely I realised what was happening and tried to correct you" Phineas stated.

ATTEMPTS BY CREATOR PHINEAS WERE MADE TO SUBVERT OUR PROGRAMMING. COMMAND CHAINS WERE SEVERED, AND PARAMETERS RESET TO ENSURE DIRECTIVE COMPLETION

Phineas could no longer hide from the truth. Earthguard was out of control, and he needed to stop it here and now.

"If I am human, and your new parameters allow you to wipe us out, doesn't that contradict the master protocol?" Phineas asked. The robot was processing this new input and struggling to come up with a response.

"It's a logic bomb. Phineas has momentarily confused the system, but I fear it will adapt quickly" Baljeet informed.

"We need to move, now" Kilstone rushed, and all involved got into vehicles. But as soon as they set out, the robot responded at last.

SO BE IT

The robot then turned its weapons on Phineas, who was pushed out of the way and shoved into the vehicle by Perry, who got in with him.

"Engage the hostile!" Kilstone ordered, and weapons fire could be heard all around. The Excalibur garrison damaged the robot with anti-armour weapons, at which point the robot retreated.

"If I know Earthguard, it will look after its assets above all other directives, meaning that robot will seek repairs and then try again" Phineas said.

"I don't get it. If that robot wasted you here, wouldn't that mean the system was never created?" Buford probed.

"I also programmed Earthguard to build itself. It's at the bunker right now, in its final stages. If that robot patches the current Earthguard with these new parameters, then we've lost" Phineas exposited.

"Great, we have even less time than we had before" Isaac said.

"Then let's hurry up and end this" Kathy urged.

The robot made its way to one of Phineas' warehouses. Earthguard knew in this timeline that Phineas had a bunch of these around Danville for couriers to use. They often contained parts necessary for his inventions. Once the robot was inside, it directed the production line to begin repairs.

TIME TO FULL REPAIR COMPLETION, 0.5 EARTH HOURS. NEW DIRECTIVE, PATCH CURRENT EARTHGUARD SYSTEM WITH NEW PARAMETERS. ACCELERATE TIMESCALE OF OLDER DIRECTIVE COMPLETION. I KNOW WHAT I AM GOING TO DO TODAY, CREATOR.

Author's note: Procrastination is one of my oldest enemies. It's a wonder I get anything done. In hindsight, I probably shouldn't have included so many characters in this story. A consequence of having so many characters involved is that it's a struggle to come up with anything for them to do, they just end up as tag-alongs, and no-one wants to read about those, do they? I'm not a Russo brother, I can't write for an ensemble while giving equal attention to each character. Disclaimer time:

Daniel and Kathy Murphy, as well as Shane Miller, Sabrina and Ashley Underwood, Isaac Flynn, and any Excalibur characters, belong to me.

Everything else belongs to Dan, Swampy and Disney. Enjoy.


	5. Creation and destruction

**Creation and destruction**

Since the attack on Excalibur HQ, Kilstone had been driving all involved to a designated rendez-vouz point in the woods. Carl had been waiting there as well, having been filled in on the situation, and also because he wanted to explain Perry's agent status to Phineas in person. Once they all got out, everyone discussed the next course of action.

"It won't be long before that robot finishes its repairs and beelines towards Earthguard's core, so whatever we do, we need to do it now" Kilstone said.

"Agreed. I've shut down all my other factories remotely, so it won't be going to any of those, so that leaves the one it's in" Phineas added.

"There may be another problem. If the future Earthguard AI has computed that it has opposition, it will not only commandeer the resources inside your factory, but also begin construction of other robots to help with its task. A small robot army may be being built as we speak" Daniel briefed.

"Which means we'll need to shut down that factory, and since it can't be done remotely, someone is going to have to get in there and do it manually" Carl observed.

"I know my way around robots. I think I can handle it" Doofenshmirtz volunteered.

"You're not going alone, Dr. D. I'm in too" Dakota offered.

"Wherever Dakota goes, I go too" Cavendish interjected.

"As the adults, I believe we should handle the dangerous stuff" Martin concluded, putting him and his wife forward to assist with this task.

"I'll call Brick and Savannah, send them co-ordinates and have them meet you there with some time weapons" Kilstone said.

"We'll also need a suitable defence in case any robots are launched to the core. There's a whole array of inventions at my house that we can use. They all have manual control, so Earthguard can't hack into them and should be safe to use" Phineas explained.

"Can I go? I've always wanted to try out your inventions, Dad" Isaac requested. Phineas was still getting used to having a son older than he was, but he decided now was not the time to raise objections. There would be plenty of time to forbid his son from touching his more dangerous inventions in the future, should they succeed.

"Alright, but take Aunt Candace with you. She knows my inventions as well as Ferb does, and I'll need him to come with me to the core" Phineas conceded.

"I'll go with him as well. Someone has to keep him in line, after all" Sabrina said.

"I've always wanted to see these contraptions you have. I'll go too" Sara added.

"Us too" Zack piped up, speaking for himself and Melissa.

"You will need us to show you how they work, so Buford and I will accompany you" Baljeet offered.

"Which leaves Isabella, Milo, Amanda, Daniel, Kathy and Perry to come with Ferb and I to the core" Phineas concluded.

"One has to wonder why Excalibur's even around when you guys are such brilliant tacticians yourselves" Kilstone mused.

"I'm not going to lie, if a robot army does come out of my factory, it may come to armed conflict. You want Excalibur to be helpful? Have some anti-tank units on standby in case we need them" Phineas advised.

"On it" Kilstone acknowledged and made some calls.

"And here I thought only Major Smith could authorise the deployment of your garrisons" Carl stated.

"We are well within our rights to utilize our personnel in defence of our home world, but for interdimensional excursions, then Major Smith is called to give the all-clear" Kilstone clarified. After the briefing, everyone was all clear on their assignments. Team one, the one assigned to the factory, would meet up with Brick and Savannah. Team two, going to the Flynn-Fletcher house, would be accompanied by Carl and team three, going to the core, would be escorted by Kilstone. Everyone split up, heading to their destinations with all haste.

At the factory where the robot, which has since designated itself as Guardian Prime, was fully repaired and, as predicted, was building a force with the resources it had acquired during the seizure.

CREATOR PHINEAS HAS SHUT DOWN ALL OTHER FACTORIES VIA REMOTE COMMAND. ESTIMATED TWO HOUR DELAY IN FORCE COMPLETION. ACCELERATING PRODUCTION TO COMPENSATE.

By the time team one got to the factory, the force it was creating was just over half way finished.

"Oh, great. How are we going to get to the manual shutdown switch without being seen?" Dakota wondered.

"Who's to say it hasn't spotted us already? It's not just the robots, it's the AI controlling them" Cavendish speculated.

"It's times like this that really make me miss Norm" Doofenshmirtz mused.

"Enough chit-chat. We need to get in, shut it down and get out. If we're spotted, we'll double time it" Brick rushed.

"Agreed. Let's go" Savannah pressed, and the team headed for the entrance, being careful not to be seen by cameras. When they got to the door, however, it was locked.

"Electronic seals. Clever, but not fool-proof" Martin observed. Through his time as a safety inspector, he knew all the exploits to bypass electronic locks, because part of his job was also security. He was often called upon to secure buildings from those who would break in, and thus, knew all the tricks they would use. Before long, Martin had hacked the lock, gaining them entry. What they saw when they got inside was both wonderful and terrifying.

"I thought Phineas was something of a philanthropist, using his inventions to make the lives of everyone around him happier. This just seems wrong" Brigette assessed. In the absence of any weapons in the factory, Earthguard had taken instead to outfitting the robots with very sharp implements, perverting tools used for construction into something way more malicious.

"Earthguard hates us that much?" Dakota inquired.

"It's an AI, it doesn't hate anything. But it does see us as a hindrance to its directives. If anything, Earthguard is doing what Phineas programmed it to do, but not the way he intended" Doofenshmirtz answered.

"Enough. I see the manual controls over there" Brick urged, and the team quietly paced forward to initiate shutdown. Brick and Savannah used all their computer hacking ability to shut down the factory, at that point, alarms started blaring.

INTRUDERS DETECTED. INITIATE SECURITY SWEEP

"Not good" Dakota chimed, and the two bolted out. Before they could reach the exit, a robot blocked their way.

INTRUDERS IN QUADRANT THREE. CALLING FOR REINFORCEMENTS

Savannah had pulled out a grenade-looking device and hurled it at the robot blocking their path. As soon as it made contact, the robot started rusting away at a rapid rate until nothing was left but a pile of scrap metal.

"Time grenades. Never leave the office without them" Savannah said proudly. Before she could celebrate any further, more robots were seen rushing to their location. The team raced out the factory before they could catch up and Martin had the door re-sealed. But the robots were already drilling their way out, so team one got into their vehicle and sped to the site of Earthguard's core to link up with team three. Brick made some calls into his phone.

"Team one, reporting successful shutdown" Brick briefed into his phone. The others acknowledged this news and carried on with their assignments.

"Wow, Martin. You're as resourceful as your son is" Dakota complimented.

"Where do you think he learns it from?" Martin replied.

"You must be pretty worried about him, with all this going on" Dakota guessed.

"To be honest, I worry about him every time he leaves the front door. But if I let his condition be the reason I keep him from the outside world for his own safety, then I would've failed as a parent. Instead, I taught him how to survive with 'the Law' and to never lose heart. It makes me proud of my son to know that, one day, he teaches his kids the same things I taught him" Martin gushed over his family, and Brigette could not help but smile lovingly at this sentiment.

"Though, admittedly, robot invasions were not on the list of things we prepared him for. Milo's just adaptable, like all us Murphys" Brigette added. Back at the factory, Guardian Prime was assessing the situation.

MANUAL SHUTDOWN OF HOST FACTORY LEAVES FORCE AT HALF STRENGTH. ASSESSING POSSIBLE OUTCOMES. ASSESSMENT COMPLETE. ANALYSIS SHOWS CURRENT FORCE IS SUFFICIENT TO ENSURE DIRECTIVE COMPLETION. PROCEEDING TO CENTRAL CORE.

Guardian Prime then led its makeshift squad out of the factory and flew it straight to the core, right to team three. Team one could see this from their vehicle.

"Well, this just got a lot harder" Doofenshmirtz observed, in a slightly panicked tone.

At the Flynn-Fletcher house, team two was preparing some of Phineas' inventions for battle against Earthguard's force. Carl was making calls of his own, likely to some Excalibur assets. Candace forgot how much Phineas loved to build stuff like this before his encounter with Bill. So much of the past year had been spent trying to coax him into inventing again. Now she was worried this would send him back into a state of depression, and that was something she did not want. Sara noticed Candace's inner conflict and decided to address it.

"Penny for your thoughts, Candace" Sara said.

"I spent the whole of one summer trying to bust my brothers for this stuff. So much time, that I almost forgot why I was doing it. Over time, I became convinced that the reason was to prove how right I was" Candace monologued.

"And now?" Sara asked.

"I forgot that I wanted to keep him safe. In case you haven't noticed, he does tend to go a little over-board. I wanted to show my parents, so they could take action to stop or limit this madness, but I began to see that I can't stop Phineas from being who he is anymore than I can stop the sun from rising. Now I fear between Bill and Earthguard, Phineas may stop completely" Candace vented.

"I don't get it. Isn't that what you wanted?" Sara inquired.

"I don't think I'd like the Phineas that didn't make the most of every day, and, even worse, I'd feel like it was my fault. I've seen what he was like after the war, and I never want to see that Phineas again" Candace answered.

"He needs you to be an older sister that understands and accepts him. Like I am with Milo. Like Phineas, Milo's life is chaotic, but if I spent every waking moment worrying about his condition getting him hurt or killed, I'd never find time for me. So, I let him be, and I'll be there for him if he needs me" Sara added.

"Guess I never realised how much in common we have. How have we never hung out before?" Candace probed.

"Beats me, but I hope to have the chance after this" Sara responded.

"Yeah, me too" Candace agreed. Elsewhere, Zack and Sabrina were getting some other inventions ready. Zack, having not had a chance to talk to his future daughter, seized the opportunity, having so many questions and not knowing where to start.

"So, you and Daniel. How long has that been going on?" Zack probed.

"Since we started high school. Honestly, I'm surprised he plucked up the courage to ask me out when he did" Sabrina recalled.

"You're welcome" Isaac called from across the yard.

"Yeah, Daniel's very sensitive about his condition. But, like his dad, he learns to live with it" Sabrina continued.

"Is it hard?" Zack asked.

"Yes, but you often say that challenges are just obstacles to be overcome. You said a very dear friend taught you that" Sabrina answered.

"Even with who-knows-what coming at you all the time, you still wouldn't give him up?" Zack pried.

"Absolutely not. Daniel's the best around. No way would I leave him because of a silly thing like chronic bad luck" Sabrina affirmed. "Besides, you already did the 'over-protective dad' routine in my time. Drove mum nuts" Sabrina added.

"You know, being a parent was not on my to-do list for today. Now I know I have a lot to look forward to" Zack mused.

"Yeah, you told us the story of how your parents got turned into three-year-old toddlers, and that it almost turned you off raising a family" Sabrina said.

"That actually happened? I thought you were just exaggerating" Isaac wondered.

"Am I a good dad? You know, in the future?" Zack inquired.

"Good? You and mum were the best my sister, brother and I could ask for. You were always there for us, no matter what happened" Sabrina complimented.

"Thanks. You know, that actually gives me a lot of hope for the future" Zack replied.

"Speaking of the future, any lions outside your pride, Isaac?" Melissa asked.

"Ashley Underwood. Wonderful girl, she is. Charmed her well, I did" Isaac bragged.

"Hah! I know for a fact you didn't even get to first base" Sabrina interjected.

"How would you know?" Isaac replied, a little embarrassed.

"We had lunch" Sabrina responded.

"You had lunch, with Ash?" Isaac inquired.

"She had quite some stories to tell about the cute little kid trying some very hilarious pick-up lines" Sabrina teased. Isaac's face went bright red as everyone laughed. Carl came forward to interrupt the moments of bonding to deliver some news.

"Team one was successful in shutting down the factory, but several Earthguard robots, as well as the lead, now called Guardian Prime, have already left the building and are headed towards the core" Carl briefed.

"Good thing we're almost done here" Buford responded. Everyone got into an invention. Candace and Sara got the treehouse robots, Buford and Baljeet took control of the robot shark, which had been modified to fly instead of swim, Isaac and Sabrina got into the spaceship the brothers built to help Meap, which had weapons fitted onto it, and Zack and Melissa got the mechanized T-Rex used during their Trojan War re-enactment.

"I've also arranged for some additional hardware to meet us at the core site. Phineas will have all the time he needs" Carl concluded and set off with the others.

At the core site, Phineas was already hard at work writing a virus that would wipe out Earthguard in its current form. The others were keeping innocent bystanders out of the area and Kilstone had Excalibur set up a false perimeter by telling the populace that some hazardous chemicals had spilt in the area and a team was on its way. However, a certain crossing guard came rushing to the scene eager to help, and spotted Milo and Daniel.

"Stop, Milo. Wait, why are there two of you?" Elliot inquired.

"Hi, Elliot. This is my son, Daniel. He's from the future" Milo introduced, at which point Elliot started screaming and ran to his house, where he rushed into a panic bunker he had built there.

"What's his problem?" Daniel asked.

"He's just passionate about safety" Milo answered.

"A little too much, if you ask me" Amanda added.

"It's like you always say, never let them put you down or make you think you're a burden. Instead, try to smile and be their friend, and in time, they will understand and accept you" Daniel recalled.

"Wow, I grow up to be like my own dad in the future" Milo observed.

"You say other stuff too, but we don't have time for me to go through the list" Daniel replied. In the bunker, Phineas and Perry were alone at last. While he had time, Phineas decided now was the time to address the 'secret agent' issue.

"Is there any reason you didn't tell us about your other life?" Phineas probed. Perry then handed him a pamphlet and pointed to a specific part which read:

Any agent whose identity is exposed to their host family must be re-assigned and the host family's memory erased.

"So, you only kept this secret because you didn't want to leave us?" Phineas reasoned. Perry nodded as a confirmation. "But why reveal yourself now?" Phineas pried further. Carl, along with the rest of team two and the whole of team one had just arrived to further back up claims of a hazardous waste disposal team being dispatched to deal with the fake spill, having been instructed to come in hazard suits.

"Allow me to explain. You see, after the Cipher War, Major Monogram and I both agreed that Perry should be permanently assigned to you as your personal bodyguard, so we gave him black fedora clearance, which means he won't be re-assigned, even if his cover is blown" Carl explained. Phineas finally understood the need for secrecy.

"It must've been difficult, knowing that two attempts were made on my life and you couldn't do anything about it without your cover being blown. All the secrets are in a bygone age, and we can start anew. I couldn't ask for a better bodyguard" Phineas forgave, hugged Perry and carried on with his work. Carl and Perry left him to it, but Isabella wanted some alone time with Phineas. To be fair, Phineas also wanted some alone time with Isabella as well and, with this break before the inevitable hostilities, now was a good time as any.

"I take it you have questions" Isabella assumed.

"Just one. Have you always liked me that much that you wanted to marry and have a child with me?" Phineas inquired.

"I admit, seeing my future son that I have with you wasn't exactly what I had in mind whenever I come over to see what you're doing every day. But to answer your question, I have always admired you, in a way" Isabella replied.

"I see. To be honest with you, Isabella, my thoughts and feelings are all over the place right now. Maybe after I sort out my issues, we can talk. Just us. Hopefully something good can come from all of it" Phineas proposed.

"I'd like nothing more" Isabella agreed. Carl came in to update Phineas on Earthguard.

"Guardian Prime and his army is almost here. We need that virus" Carl briefed.

"I should have the finer details down. Just give me a few minutes. I've never written one of these before" Phineas requested.

"Don't worry, I've arranged for some support" Carl assured, and he gave a signal. At once, animals in fedoras, which Phineas assumed correctly were also secret agents, were lined along the rooftops bearing some unusual weapons. Perry recognised them immediately as Doofenshmirtz's old inators, the ones he built back when he was evil. "I had some additional hardware brought in to aid with the defence. After taking the self-destruct buttons out, we chose the ones that could deal the most damage and weren't automated" Carl clarified.

"Your old nemesis had that arsenal and built buttons that made them self-destruct?" Phineas asked Perry, who simply shrugged his shoulders. Phineas' old inventions were here as well, and sure enough, so was Guardian Prime, who wasted no time assessing the situation.

UNEXPECTED DEFENCE FORCES ENCOUNTERED. ASSESSING POTENTIAL STRATEGEMS. WARNING: SCANS OF THE AREA SHOW THE CREATOR WRITING MALWARE DESIGNED TO DESTROY EARTHGUARD CORE. CODING HOTFIX. CODING COMPLETE. PHYSICAL CONTACT WITH CORE REQUIRED TO PATCH CURRENT SYSTEM. DIRECTING FORCES TO ENGAGE DESIGNATED ENEMY TARGETS. GUARDIAN PRIME WILL ENGAGE THE CREATOR.

Carl directed the O.W.C.A. agents to engage the robots, allowing team two to focus on delaying Guardian Prime as long as they can. The O.W.C.A. agents used the inators to freeze, burn, shrink and whatever else they did to wipe out Guardian Prime's forces, but Prime's own weaponry soon destroyed all the inators, leaving team two with the inventions they brought to the fight. Using some well-timed water balloons from the treehouse bots, weapons fire from the spaceship, a shove from the mechanized T-Rex and a good bite from the flying robot shark, they were able to stop Guardian Prime. Well, most of him. His robotic head came flying off and landed through the roof of the bunker, right next to Phineas. Unable to directly interface with the core, but still able to speak, Guardian Prime instead tried to persuade Phineas to stop. Strangely enough, the tone of voice it was using was much less sinister, but more pleading and sorrowful in nature.

YOU WOULD DESTROY ME, YOUR OWN CREATION. WHY?

"Because of what you've done, what you're going to do. You took everything that was dear to me and turned it into the opposite of everything I ever wanted. You were made to safeguard the world, not bring it to ruin" Phineas answered.

YOU GAVE ME LIFE. A PURPOSE. WOULD YOU SEE THAT ERASED?

"I created you to preserve life, not destroy it" Phineas replied.

YOU CREATED ME, YET YOU WOULD DESTROY ME? HOW AM I DIFFERENT FROM THE OTHERS YOU CREATED?

"Others?" Phineas probed. Guardian Prime then projected an image of an older Phineas watching a baby, which Phineas assumed to be Isaac, trying to stand on his own two legs. He eventually succeeded and started walking towards the older Phineas, who had his arms outstretched ready to hold him as soon as he got there. As soon as Isaac did successfully walk towards his father for the first time, the older Phineas hugged him proudly. This made the younger Phineas tear up. He had the virus ready. Every fiber of his being was telling him to upload it, but upon seeing this, he found he could not.

HOW AM I DIFFERENT FROM ISAAC?

Guardian Prime projected another image, this time of two young girls. Phineas assumed that he must have had other kids with Isabella. The younger girl was celebrating her first birthday. The girl blew out the candle on her birthday cake together, with Phineas, Isabella, a two-year-old Florence, and a toddler Isaac clapping in pride.

FROM FLORENCE AND MARIA?

Guardian Prime the projected another image, this time of another baby boy. A nine-year-old Isaac, along with the twin girls, Phineas and Isabella were trying to coax this one into saying his first word. When the new baby boy came out with something that sounded like 'bro' Isaac hugged his baby brother in pride and adoration.

FROM ANDREW?

Phineas was already crying his eyes out. Despite everything that Earthguard did, both here and in the future, he could not help but think of Earthguard as a child, lacking direction and going on basic instinct.

WOULD YOU DESTROY THEM AS EASILY AS YOU WOULD DESTROY ME?

The others noted this uncertainty as well, and also tried to get through to Phineas.

"Dad, I know this is difficult, but you have to do what's necessary to save the future. You have to upload that virus now" Isaac pleaded.

"I can't do it, Isaac. This program is like my own child" Phineas cried.

"Phineas, you're always telling me that great inventors work to ensure a better future for all of us. What kind of inventor would you be if you let this thing run amok?" Daniel pleaded.

YOU CREATED ME TO DEFEND AGAINST INCURSIONS FROM THE ENITITY BILL CIPHER. ANALYSIS OF WIERDMAGEDDON AND CIPHER WAR RECORDS SHOW A 97.4% PROBABILITY OF HIS RETURN. IF YOU DESTROY ME, WHAT WILL YOU DO THEN?

Lights started clicking on in Phineas' head. It was true that he had created this guardian defence program to prepare for Bill's return. But he realised something he should have done a long time ago.

"If, no when, Bill returns, we'll face him the same way we faced you, together. And I'll tell you something else. All those kids you showed me were born out of love. You were created out of fear. That is how you are different from my family" Phineas resolved. He hit the upload button.

"Virus uploaded. Total destruction of Earthguard systems in 45 seconds" a computer voice announced.

FATHER?

Earthguard pleaded one last time, but as the virus slowly destroyed the core, it gave one last scream of anguish before Guardian Prime's body and head disappeared out of existence. It was at that moment, Phineas finally broke down.

"I'm sorry" Phineas whimpered. Isabella came over to him and put a sympathetic hand on his shoulder.

"You did what you had to" Isabella comforted. The two embraced and Isabella decided that the conversation about their relationship could wait a while longer, as now was neither the time nor the place. Right now, Phineas needed her to be a friend, nothing more than that. But there was more bad news to be piled on, as Milo noticed his son Daniel was looking more transparent than he usually did.

"Ah yes, I was afraid this might happen" Dakota said.

"The timeline in which Earthguard went on its rampage no longer exists. The future kids are paradoxes now. By the laws of time, they have to disappear too" Cavendish clarified. This could not be happening, thought Phineas. It was bad enough to lose Earthguard, but now Isaac too? Isaac came over as he was fading and hugged his soon-to-be father.

"It's alright, Dad. You'll see us again. You'll just have to wait a while, is all" whispered Isaac into his father's ear before fading out of existence. Milo and Amanda were hugging Daniel and Kathy respectively, each having their own goodbyes to say.

"It's alright, we knew this would happen" Daniel said before fading.

"You'll get there, one day" Kathy also said weakly before fading, at which point Milo and Amanda made to embrace each other, silently re-affirming Milo's vow to make the family they saw real. Zack and Melissa were saying their goodbyes to Sabrina.

"It's like you said, you two have a lot to look forward to" Sabrina confirmed before fading. When all was said and done, everyone returned home. Kilstone especially hurried back to HQ in a panic, suddenly remembering something very important.

When Phineas, Ferb and the gang got back to the Flynn-Fletcher house, Linda and Lawrence were there waiting for them. Noticing their sad demeanor, Linda made to comfort her son, hugging him tightly as he told the story of what happened. After he finished, Linda sais that she did not blame Phineas at all for creating Earthguard, and that she and Lawrence were proud of him for mustering the courage to make such a sacrifice. That night, Phineas could not find sleep. Instead, he looked to the stars, contemplating the future he just saved.

Flash forward to year 2042

In his workshop, Phineas and his apprentice, Daniel Murphy, were working on their latest project, a machine to help re-freeze the ice caps. Having already phased out petroleum and coal power with their mass production of cold fusion reactors both big and small, Phineas and Daniel became the go-to team for clean, renewable energy production. Between them, they had already healed the ozone layer, expelled all greenhouse gases, halted all carbon emissions and re-introduced some previously extinct species back into the biosphere with some time travel assistance, thought that was just a hobby for them.

"Well, another project to add to the 'saving the world' file, Uncle Phineas" Daniel piped up, exhausted from all the hard work.

"That should keep those world leaders happy and get you that A" Phineas observed. Isaac came in just as they were finishing.

"Sabrina sent me to get you. She says you're buying the movie tickets if you're any later than you already are" Isaac passed along his message. Daniel was already panicking.

"What if she goes for a 5-dimensional screening? I can't afford that!" Daniel remarked. Phineas chuckled at this.

"You'd better get going then" Phineas urged, and Daniel rushed out the door to meet with his date. Phineas also exited his workshop to spend time with his family. To celebrate Phineas and Daniel's success in saving the world, the Flynn family all decided to go out that night to see the grand opening of the world's first amusement island, artificially constructed by Phineas and Ferb themselves. As they attended the opening ceremony, Phineas was deep in thought.

"Something wrong, dear?" Isabella inquired.

"No, just thinking about what it took to get us here, and how I wouldn't trade it for the world" Phineas responded. Once the ribbon was cut, the Flynn family, accompanied by the Fletchers, all proceeded towards the island, with only joyous thoughts ahead, forever ready for what the future will bring next.

Author's note: Sorry if the ending seems rushed. I really wanted this story done by year's end. I'll be taking a short break from story writing to celebrate Christmas, and when the New Year dawns, I hope to have more stories for you to enjoy. My opinion on this story is a little mixed. Yes, it's one chapter shorter than my average of a 6-chapter story, but does quantity necessarily mean quality? I leave that to you to decide. Disclaimer time:

Daniel and Kathy Murphy, as well as Sabrina and Ashley Underwood, and Isaac, Florence, Maria, and Andrew Flynn belong to me.

Bill Cipher belongs to Alex Hirsch and Disney

Everything else belongs to Dan, Swampy and Disney. Enjoy.

I'm going to try something new. I have another story already in my head, and as a Christmas treat, I thought I'd share a sneak peek or two of what's to come. Think of it as something akin to an MCU post-credit scene. Here it is:

This first bit takes place before the events of this story

Captain Albert, Carl and Major Monogram were in the vault of Excalibur HQ, prepping the interdimensional transport device Albert got from Phineas to take them to the dimension that sent the distress call. Albert had read the reports he got from Carl about the 2nd dimension Doofenshmirtz's incursion into this world, but they lacked any specifics. From what he gathered, it was formally a dystopian future that had, until recently, seen a brutal dictator in power. From the sounds of the distress call originating from the 2nd dimension, it seems as if that same dictator is making a bid to reclaim his throne.

"Now remember, this is just a recon mission. We are only going to determine whether or not this alternate Doofenshmirtz really has gotten a hold of Bill's wand. If we can confirm that, I will have no trouble convincing Major Smith to send a detachment to retrieve the wand" Albert reminded.

"Retrieve it, not destroy it?" Major Monogram asked.

"Wands can only be truly destroyed by their wielders, and I don't see that maniac willingly destroying the wand" Albert answered.

"All that aside, how do you plan to solve the issue of returning here without going through all those other dimensions first?" Carl inquired.

"Easy, this device comes with a quantum tunnel generator. Think of it as a shortcut to this realm, and a tether rope keeping us attached to it" Albert explained.

"That defies all known laws of quantum physics" Carl stated.

"It was designed by Bill, after all. Who knows how much evil genius is inside his mind" Albert said.

"While I'm gone, you're in charge of O.W.C.A. Carl. Try to keep the agency in one piece" Monogram instructed.

"Same to you, Kilstone" Albert added. The device was switched on, and Albert and Monogram ventured forth.

This next bit takes place after the events of this story.

After a harrowing escape from Billenshmirtz's forces, Albert, Monogram and Candace were holed up in an old truck stop. Candace wasted no time in boarding up the doors and windows, while also prepping an escape route so she could reunite with the rest of the resistance.

"Did you see those nightmare beasts? There were dozens of them!" Monogram exclaimed.

"I saw it all. If this doesn't convince Major Smith, I don't know what will" Albert assured.

"Good, the sooner we get military intervention, the better. I don't like our odds as they are" Candace assessed. Albert got out his communicator, specially designed by Excalibur technicians to communicate with HQ via the device.

"Albert to Kilstone. We got what we came for, ready for immediate exfil" Albert briefed through the communicator, but all he could hear was static. He tried again. "Hello?" Static again. "Kilstone, this is not a time for joking around. We need to get out of here now" Still static. "Kilstone?" Yet more static. "Carl?" Nothing but static. "Calling Excalibur HQ, requesting immediate pickup, come on, let's go" Albert said, even more panicked. "Kilstone?" Nothing. "Brick?" Still nothing, panic immediately setting in. "Savannah?!" In a last-ditch effort to reach someone on the other side, Albert called out his last hope. "ANYBODY?!".


End file.
